Add extra checks to avoid crashes with broken vqf files

git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@28149 b3059339-0415-0410-9bf9-f77b7e298cf2

1 files changed, 11 insertions, 6 deletions

diff --git a/libmpdemux/demux_vqf.c b/libmpdemux/demux_vqf.c
index 3578803b66..3aefa02dd9 100644
--- a/libmpdemux/demux_vqf.c
+++ b/libmpdemux/demux_vqf.c
@@ -51,11 +51,14 @@ static demuxer_t* demux_open_vqf(demuxer_t* demuxer) {
     unsigned chunk_size;
     hi->size=chunk_size=stream_read_dword(s); /* include itself */
     stream_read(s,chunk_id,4);
+    if (chunk_size < 8) return NULL;
+    chunk_size -= 8;
     if(AV_RL32(chunk_id)==mmioFOURCC('C','O','M','M'))
     {
-    char buf[chunk_size-8];
+    char buf[BUFSIZ];
     unsigned i,subchunk_size;
-    if(stream_read(s,buf,chunk_size-8)!=chunk_size-8) return NULL;
+    if (chunk_size > sizeof(buf) || chunk_size < 20) return NULL;
+    if(stream_read(s,buf,chunk_size)!=chunk_size) return NULL;
     i=0;
     subchunk_size      = AV_RB32(buf);
     hi->channelMode    = AV_RB32(buf + 4);
@@ -84,13 +87,15 @@ static demuxer_t* demux_open_vqf(demuxer_t* demuxer) {
     sh_audio->samplesize = 4;
     w->wBitsPerSample = 8*sh_audio->samplesize;
     w->cbSize = 0;
+    if (subchunk_size > chunk_size - 4) continue;
     i+=subchunk_size+4;
-    while(i<chunk_size-8)
+    while(i + 8 < chunk_size)
     {
         unsigned slen,sid;
-        char sdata[chunk_size];
+        char sdata[BUFSIZ];
         sid  = AV_RL32(buf + i); i+=4;
         slen = AV_RB32(buf + i); i+=4;
+        if (slen > sizeof(sdata) - 1 || slen > chunk_size - i) break;
         if(sid==mmioFOURCC('D','S','I','Z'))
         {
         hi->Dsiz=AV_RB32(buf + i);
@@ -142,7 +147,7 @@ static demuxer_t* demux_open_vqf(demuxer_t* demuxer) {
     if(AV_RL32(chunk_id)==mmioFOURCC('D','A','T','A'))
     {
     demuxer->movi_start=stream_tell(s);
-    demuxer->movi_end=demuxer->movi_start+chunk_size-8;
+    demuxer->movi_end=demuxer->movi_start+chunk_size;
     mp_msg(MSGT_DEMUX, MSGL_V, "Found data at %"PRIX64" size %"PRIu64"\n",demuxer->movi_start,demuxer->movi_end);
     /* Done! play it */
     break;
@@ -150,7 +155,7 @@ static demuxer_t* demux_open_vqf(demuxer_t* demuxer) {
     else
     {
     mp_msg(MSGT_DEMUX, MSGL_V, "Unhandled chunk '%c%c%c%c' %u bytes\n",chunk_id[0],chunk_id[1],chunk_id[2],chunk_id[3],chunk_size);
-    stream_skip(s,chunk_size-8); /*unknown chunk type */
+    stream_skip(s,chunk_size); /*unknown chunk type */
     }
   }